Pensions and Other Postretirement Benefit Plans (Schedule of Expected Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions in the next fiscal year	$ 37,144
2012	23,160
2013	24,087
2014	23,551
2015	23,656
2016	24,094
2017 - 2021	123,344
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions in the next fiscal year	5,949
2012	5,949
2013	5,765
2014	5,577
2015	5,354
2016	5,174
2017 - 2021	$ 24,195

The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph g

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant